A battery pack having a cooling plate assembly and a battery module is provided. The cooling plate assembly has a pan member, first and second corrugated support members, a cover plate, and a thermally conductive layer. The pan member has first and second depressed plate portions. The first and second corrugated support members are disposed on the first and second depressed plate portions, respectively. The cover plate is coupled to the pan member such that the first and second corrugated support members are held between the cover plate and the pan member in first and second internal regions, respectively, defined by the cover plate and the pan member. The thermally conductive layer is disposed on the cover plate. The battery module is disposed on the thermally conductive layer.